Business Insider attended the company’s press conference in Barcelona and got some hands-on time with both devices.

The S9 and S9 Plus will go on sale March 16, but customers will be able to preorder it on Friday.

Here are the key takeaways for those considering buying either phone.

The design has remained virtually unchanged.

Edoardo Maggio/Business Insider

The first thing that’s immediately noticeable upon picking up a Galaxy S9 or a Galaxy S9 Plus is just how similar they are to their predecessors.

The same 5.8- and 6.2-inch displays dominate the devices’ front, an aluminium strip goes around the edges, and a glass back shimmers.

If you didn’t notice the different positioning of the fingerprint sensor – which now comfortably sits below the camera instead of next to it – or stumbled upon one of the new colours like “lilac purple,” you would have a hard time telling a Galaxy S9 from the Galaxy S8.

Samsung’s new phone seems a lot like the “S” versions of the iPhones in years past, but that’s not to say the design has any noticeable flaws. The in-hands feel remains solid.

There are some upgrades, but many of the specs are similar.

Edoardo Maggio/Business Insider

But similarities between the Galaxy S8 and the Galaxy S9 don’t end there.

Those “infinite display” panels are still QuadHD, the screen resolution introduced in 2015 with the Galaxy S6 and the Galaxy S6 Edge. And while they still look as good as ever, they fail to impress anymore.

That’s not a call for 4K displays on sub-7-inch displays – but a QuadHD display alone struggles to add anything that previous smartphones didn’t have, and therefore the very first impression can’t be “wow.”

Samsung has consistently had some of the best panels on the market, so the slight improvements in brightness and colour accuracy on the S9 get lost in the bulk of upgrades in the Galaxy S8 last year.

The S9 also retains the 3000 milliampere-hour battery its predecessor had (3500 mAh for the S8 Plus and S9 Plus), 64 GB of storage, and 4 GB of RAM for the base model. (The S9 Plus has 6 GB, but the differences in performance were unnoticeable in the brief stress test I made.)

The most notable S9 and S9 Plus upgrades are the processor, which is now the Snapdragon 845; the Note 8’s iris scanner, which can be used to unlock the device; and a new pair of stereo speakers, tuned by AKG.

Overall, however, much of last year’s Galaxy S8 has made its way to this year’s device, which is a slight refinement and not a rethinking of the Galaxy S brand.

There are also some important spec differences between the S9 models.

Edoardo Maggio/Business Insider

Perhaps the biggest difference is not between the old and the new models, but between the S9 and the S9 Plus.

The Galaxy S8 and the S8 Plus were almost identical, whereas this year’s Galaxy S9 and S9 Plus differ from each other more significantly. (This could also translate to a larger price difference, but Samsung has not shared final pricing details.)

There are four distinctions: screen, battery, RAM, and camera.

The S9 Plus’ screen is 0.4 inches larger – a nice real-estate bump, considering the difference in size is negligible, at least in your hands.

I use an iPhone X, a 5.8-inch device, as my daily driver, and I still felt that the slightly larger Galaxy S9 Plus got more value out of its added size than its smaller sibling.

The S9 Plus’ battery, on the other hand, is a full 500 mAh larger than the battery on the standard Galaxy S9, which could mean a better battery life. The extra 2 GB of RAM may also come in handy as apps get bigger and the device’s battery wears out over time.

But the major difference is the secondary 12-megapixel telephoto camera, which is on only the S9 Plus.

The dual-lens system is borrowed from last year’s Galaxy Note 8, and Samsung uses it to offer 2x zoom without quality loss and some so-called bokeh effects to enhance portrait-mode pictures.

The camera is the key difference.

Edoardo Maggio/Business Insider

The main camera, arguably the single biggest upgrade from last year’s device, is where the Galaxy S9 shines.

The sensor – identical on both phones – still maxes out at 12 MP, but the lens has been reengineered from the ground up. It now offers something of a first for smartphone cameras: a mechanical aperture.

Because smartphone sensors are so small, phone companies have stuck with fixed camera apertures and worked on things such as auto-focus technologies, dual pixels, and second lenses to improve the quality of pictures.

But the Galaxy S9’s dual aperture allows it to go as wide as f/1.5 – an ultrawide aperture that lets in a lot of light and can come in handy for low-light situations – or keep sharper detail at f/2.4.

The camera will automatically switch between the two according to the amount of light, but a pro mode will allow you to tweak most settings – like ISO and white balance, other than aperture – if you want.

The mechanical nature of the aperture’s change, much like on DSLR cameras, means you can see the difference for yourself, with the camera opening and closing its eye at the tap of a button.

There was no way to properly test the rear shooter in the dim and chaotic Samsung venue in Barcelona, but the camera is insanely fast, and its app is clean and cleverly designed.

The inclusion of a changeable aperture is a remarkable achievement – one we’re likely to see more this year as smartphones keep getting unveiled.

Augmented-reality emojis and slow-motion videos are fun, but you will soon forget about them.

Edoardo Maggio/Business Insider

The front camera, on the other hand, hasn’t changed – both the S8 models and the S9 models have the same f/1.7, 8 MP camera.

What has changed is what it’s used for, with Samsung’s introduction of augmented-reality emoji.

AR emojis are essentially the company’s take on Apple’s Animoji and work much in the same way: You take a picture of yourself, and the phone processes it into an Xbox-like avatar that can track your facial movements.

You can then either shoot video or share it via a series of premade GIFs. In my brief testing, however, the process didn’t work well, and the facial tracking was a bit hit or miss.

AR emojis don’t feel like anything more than a fun gimmick – and if Animoji has taught me anything, it’s that I would probably not find myself using AR emoji much either.

There’s also a new, impressive 960-frames-per-second slow-motion video mode, but that also doesn’t feel like a feature that can improve the phone’s daily usability. It’s fun to have, and it’s a technically spectacular feat, but there isn’t much to it beyond that.

It will probably be a great phone for Android lovers who come from older devices — but not many others.

Edoardo Maggio/Business Insider

With negligible updates in hardware and software (the demo units I tried ran on Android 8.0 Oreo) the Galaxy S9’s overall feel was that of a slightly tweaked Galaxy S8.

If you own a Galaxy S8 or any other high-end Android smartphone, like Google’s Pixel 2 XL or even Samsung’s Note 8, there isn’t much for you to look forward to here.

Samsung didn’t want to revolutionise the experience, and you’ll probably be better off waiting another year – or at least for the Galaxy Note 9 – before considering an upgrade.

But if you own an older smartphone, the Galaxy S9 models may represent one of the two best options you can get your hands on right now in the Android market.

Beyond the obvious comparisons with its predecessor that make the leap appear small, the S9 Plus is a great package – particularly in the design, display, and camera departments.

The Galaxy S9 and S9 Plus come out on March 16, so keep an eye out for Business Insider’s full review soon.

NOW WATCH: Tech Insider videos

Want to read a more in-depth view on the trends influencing Australian business and the global economy? BI / Research is designed to help executives and industry leaders understand the major challenges and opportunities for industry, technology, strategy and the economy in the future. Sign up for free at research.businessinsider.com.au.